Optical Nanoprocessing Lab, Department of Mechanical Engineering, BK21 FOUR ERICA-ACE Center, Hanyang University, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, 15588, South Korea.
Department of Mechanical Engineering/Institute of Engineering Research, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea.
Adv Mater. 2023 Jun;35(22):e2212294. doi: 10.1002/adma.202212294. Epub 2023 Apr 19.
Physical unclonable functions (PUFs) are emerging as an alternative to information security by providing an advanced level of cryptographic keys with non-replicable characteristics, yet the cryptographic keys of conventional PUFs are not reconfigurable from the ones assigned at the manufacturing stage and the overall authentication process slows down as the number of entities in the dataset or the length of cryptographic key increases. Herein, a supersaturated solution-based PUF (S-PUF) is presented that utilizes stochastic crystallization of a supersaturated sodium acetate solution to allow a time-efficient, hierarchical authentication process together with on-demand rewritability of cryptographic keys. By controlling the orientation and the average grain size of the sodium acetate crystals via a spatiotemporally programmed temperature profile, the S-PUF now includes two global parameters, that is, angle of rotation and divergence of the diffracted beam, in addition to the speckle pattern to produce multilevel cryptographic keys, and these parameters function as prefixes for the classification of each entity for a fast authentication process. At the same time, the reversible phase change of sodium acetate enables repeated reconfiguration of the cryptographic key, which is expected to offer new possibilities for a next-generation, recyclable anti-counterfeiting platform.
物理不可克隆函数（PUF）作为信息安全的替代方案而出现，它提供了具有不可复制特性的高级加密密钥，但传统 PUF 的加密密钥不能从制造阶段分配的密钥中重新配置，并且随着数据集或加密密钥的长度增加，整体认证过程会变慢。在此，提出了一种基于过饱和溶液的 PUF（S-PUF），它利用过饱和乙酸钠溶液的随机结晶来实现高效、分层的认证过程，同时还可以按需重写加密密钥。通过控制时空编程温度分布，可以控制乙酸钠晶体的方向和平均晶粒尺寸，S-PUF 现在除了产生多级加密密钥的散斑图案外，还包含两个全局参数，即衍射光束的旋转角度和发散角，这些参数作为每个实体分类的前缀，用于快速认证过程。同时，乙酸钠的可逆相变化允许重复配置加密密钥，这有望为下一代可回收防伪平台提供新的可能性。
